----- Original Message ----- > Hi,
Hey Steve, Good to see you around :) > I am working on Containerizing OpenStack in the Kolla project ( > http://launchpad.net/kolla ). One of the key things we want to do over the > next few months is add H/A support to our container tech. David Vossel had > suggested using systemctl to monitor the containers themselves by running > healthchecking scripts within the containers. That idea is sound. Knowing what I know about OpenStack HA now, that is a bad choice. > > There is another technology called “super-privileged containers”. Essentially > it allows more host access for the container, allowing the treatment of Yep, this is the way to do it. My plan is to have pacemaker running in a container, and have pacemaker capable of launching resources within containers. We already have a Docker resource agent. You can find it here, https://github.com/ClusterLabs/resource-agents/blob/master/heartbeat/docker Using that agent, pacemaker can launch a docker container, and then monitor the container by performing health checks within the container. Here's an example of how I'm using this technique to manage a containerized apache instance. https://github.com/davidvossel/phd/blob/master/scenarios/docker-apache-ap.scenario#L96 > Pacemaker as a container rather than a RPM or DEB file. I’d like corosync to > run in a separate container. These containers will communicate using their I actually already got pacemaker+corosync running in a container for testing purposes. If you're interested you can checkout some of that work here, https://github.com/davidvossel/phd/tree/master/lib/docker . The phd_docker_utils.sh file holds most of the interesting parts. > normal mechanisms in a super-privileged mode. We will implement this in > Kolla. > > Where I am stuck is how does Pacemaker within a container control other > containers in the host os. One way I have considered is using the docker > —pid=host flag, allowing pacemaker to communicate directly with the host > systemctl process. Where I am stuck is our containers don’t run via > systemctl, but instead via shell scripts that are executed by third party > deployment software. > > An example: > Lets say a rabbitmq container wants to run: > > The user would run > kolla-mgr deploy messaging yes, and from there kolla-mgr hands the containers off to pacemaker to manage. kolla is the orchestration, pacemaker is the scheduler for performing those tasks. > This would run a small bit of code to launch the docker container set for > messaging. > > Could pacemaker run something like > > Kolla-mgr status messaging > > To control the lifecycle of the processes? > > Or would we be better off with some systemd integration with kolla-mgr? > > Thoughts welcome > > Regards, > -steve > > _______________________________________________ > Pacemaker mailing list: Pacemaker@oss.clusterlabs.org > http://oss.clusterlabs.org/mailman/listinfo/pacemaker > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: http://bugs.clusterlabs.org > _______________________________________________ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
